Hemera/Thinkstock(NEW YORK) -- In the first half of 2017, airlines involuntarily bumped passengers at the lowest rate in over a decade, according to newly released data from the U.S. Department of Transportation.

The 12 U.S. carriers that report incidents of involuntary denied boarding posted a bumping rate of 0.52 per 10,000 passengers compared to a rate of 0.62 from this time last year. Specifically, the second quarter of 2017 saw an even lower rate of 0.44 per 10,000 passengers, a historic low for the airline industry.

The lower involuntary bumping rate comes as airlines are reviewing their involuntary bumping or denied boarding policies after the Dr. David Dao incident on United in early April. The event caused a major public backlash as images and videos of a bloody Dao being dragged off a United flight by police flooded social media.

United Airlines settled with Dao back in late April over his removal. Oscar Munoz, United Airlines' CEO, spoke with "Good Morning America" around the same time in an ABC News exclusive interview, saying he felt “shame” over the incident.

“This will never happen again,” Munoz said. “We are not going to put law enforcement officials onto a plane to take them off ... to remove a booked, paid, seated passenger. We can’t do that.”

United and other airlines have taken steps to reduce passenger bumping, including raising their incentive payment cap for voluntary denied bumping to $10,000.

Other changes specifically in United policies specifically include “crews must be booked on flights at least 60 minutes prior to departure” and “customers already seated on a plane will not be required to give up their seat involuntarily unless safety and security is at risk.”

The Department of Transportation has also released a microsite to help passengers learn about their rights 35,000 feet up. When it comes to involuntary bumping, one right passengers have is, “DOT requires each airline to give all passengers who are bumped involuntarily a written statement describing their rights and explaining how the carrier decides who gets bumped.”

The website also states that airlines still have a legal right to involuntarily bump or deny boarding to passengers and “it is the airline’s responsibility to determine its own fair boarding priorities.”